Screw and nut



FIG. 1 discloses a top perspective view of a screw and nut of my new design;

FIG. 2 discloses an elevational view thereof;

FIG. 3 discloses a top plan view thereof; and,

FIG. 4 discloses a bottom plan view thereof.

The portions of the design shown in broken lines show unclaimed subject matter. 

CLAIM The ornamental design for a screw and nut, as shown and described. 